On the influence of mode interaction on the buckling eigenshapes of thin‐walled structures

Abstract

Some considerations on influence of mode interaction on eigenshapes of the thin‐walled structures are given. Classic theory is limited on structures with non‐deformable cross section, so that for general analysis it was necessary to apply semi‐analytical finite strip method. Strip displacement field is approximated with sum of products of trigonometric functions and polynomials, where the trigonometric functions are chosen as eigenmodes of Bernoulli‐Euler beam. Both coupled and uncoupled finite strip formulations are used. Following the presented theory, computer program which enables detailed insight into mode interaction problems is developed. Buckling and stability curves of one open ‐ section and one closed ‐ section are analysed in details. Influence of local buckling critical length of simply supported structure on dominant eigenmodes of structures with different boundary conditions and arbitrary length is indicated.